Field of the Invention
The present invention relates to a transmission for changing the power transmitted from an input shaft to an output shaft, and more particularly, to a transmission using a planetary gear.
Description of the Related Art
In general, apparatuses using power, such as machine tools, vehicles or the like do not directly use the power transmitted from a power source but change an input speed and a torque of input power by using a transmission to obtain a required speed and a torque.
Such transmissions decrease or increase the number of revolutions of an input shaft at an output shaft by using an arrangement of gears to induce a gear shift, and the gears are generally used through a method in which spur gears are coupled in multiple stages using the diameter and number of teeth thereof.
However, the existing transmissions have limitations in that since the speed change is generated by the engagement of shifting gears, noise and wear are caused by friction, and especially the power speed change efficiency is inferior due to the large size and a large installation space thereof.